Reciprocating motion for bed presses



Nov. 1l, 1947. F. R. MOLITOR RECIPROCATING MOTION FOR BED PRESSES 194644 Sheets-Sheet 2 Filed Jan. 22

F. R. MOLITOR NOV. 11, 1941 l RECIROCATING MOTION FOR BED PRESSES 4sheets-sheet s Filed Jan. 22, 1946 "ell-(ama N0v11,1947. MOU-m2,430,644v

RECIPROCATING MOTION FOR BED PRESSES File'd Jan. 22, 1946 4 Sheets-Sheet4 f Snnentor y F. Molar,"

Bg I t' Patented Nov. l1, 1947 UNITED s'mrssl QFFICE RECIPROCATING MOTGNFOR BED PRESSES 12 Claims.

My invention relates to printing presses as Well as to cutting andcreasing presses, and more particularly to the reciprocating motion forthe beds of such presses.

The principal object of the invention is to provide a reciprocatingmotion which permits easy reversal of the bed during each stroke of themachine and which, if desired, may be easily applied to existing flatbed printing presses.

A primary feature of the invention consists in mounting a rotatablepinion on a bar which is slidable back and forth, the ypinion being inconstant mesh with a rack secured to the bed of the press and beingconsecutively engageable lby eccentrically mounted means for reversingrotation of the pinion during each change in direction of movement ofthe bar.

Another feature of the invention consists in .providing a pair ofoppositely rotating gears with portions which are consecutively movableinto and out of cooperation with the pinion in mesh with a rack securedto the bed so that rotation of the pinion is periodically reversed toeffect reciprocation of the bed.

A further feature of the invention consists in providing means forlaterally shifting the axis of the pinion which is in constant mesh witha 'rack on the bed and in having a pair of meshing gears respectivelyprovided with crank arms which, during shifting of said pinion, arecaused to consecutively cooperate therewith to drive the pinion and toreverse the direction of rotation thereof during each change in thedirection of movement of the axis of the pinion.

Other and more specific features of the invention, residing inadvantageous forms, combinau tions and relations of parts, willhereinafter appear and be pointed out in the claims.

In the drawings,

Figure 1 is a perspective view of my invention as applied to a printingpress having a reciprocating flat bed.

Figure 2 is a plan view of my invention, the printing press bed beingomitted.

Figure S is a sectional View taken on line 3-3 of Figure 2.

Figure 4 is a fragmentary sectional View taken on line 4 4 of Figure 2,a portion of the rack on 'the bed ypress being shown.

Figure 5 is a fragmentary view, wherein the reversible pinion and thecrank pins are shown in elevation, which illustrates the approximateposition of parts after the gears carrying the crank arms have rotatedabout 90 from the positions shown in Figures 3 and 4 and the bar hasshifted to the right by the lactuated cam.

Figure 6 is a view similar to Figure 5 showing the position of the partsafter the crank arms have rotated 180 from the positions shown inFigures Sand 4. Y y

Figure 7 is a View similar to Figure 5 showing 2 in full lines thepinion in engagement with the other crank arm and showing in dot anddash lines the relative position of the parts at approximately the timethat the crank moves into operative engagement with the pinion.

It will be evident to those skilled in the art that the invention may beused with various types of presses having reciprocating beds, such, forexample, as the well known single or two revolution cylinder printingpress, the single or two revolution cylinder ilat bed cutting andcreasing press and two revolution cylinder flat bed two color printingpress.

Referring more particularly to the drawings, l indicates a reciprocatingbed pressand 2 a pinion which is in constant mesh with a rack 3 securedto the bed. The pinion is rotatably mounted on a shaft iwhich is carriedby a support or bar 5 slidably mounted in a box or the like G rigid withthe frame of the press, the shaft projecting through an elongated slot lat one side of the box 6.

Pivotally mounted on a supporting stud or the like 8 is an arm 9 whichis preferably bifurcated at its upper end to straddle a stud or boss li)rigid with the sliding bar 5. This arm is adapted to be moved to and froabout the stud 3 as a center to cause the bar 5 to slide back and forthin box 6. The upper bifurcated end of the arm which may advantageouslybe spaced from the bar by a spacing block ll provides a slot l2 enablingstud l i) to slide relatively to the arm when the latter is rocked toand fro.

This desired motion may be imparted to the rotating arm 9 by a cam I3rigid With a shaft It preferably driven in any convenient and well knownmanner by which the entire press is advantageously driven. The cam ispreferably of the Jtype known in the art as a box cam and is providedwith a groove or track I5 in the inner face thereof for receiving aroller I6 mounted on a pin or support il carried by the arm 9 projectinglaterally therefrom. The groove I5 in the cam is so formed with respectto the axis of the shaft l@ as to cause the arm to move to and fro aboutthe supporting stud 8 as a center and thereby cause the bar 5 to whichthe arm is connected to move back and forth.

In Figure 3 the cam is shown as having been actuated so that the arm hasbeen moved as far as possible toward the left as viewed in the ngure,and the bar 5 has been moved correspondingly in the same direction.Continued rotation of the cam by the shaft will cause the arm and thesliding bar to move toward the right, as viewed in Figure 3 until theroller I6 reaches the lower portion of the groove or track l5 which fora limited distance is concentric with the axis of the shaft. Afterleaving the smaller concentric portion of the groove, the cam thenfunctions to move the arm, and therefore, the bar 5 in the 3 oppositedirection until the roller I6 again enters a relatively longer portionof the groove concentric with the axis of the shaft, And, of course, thecam does not impart movement to the arm while the roller I6 travels inthese two portions of the groove which are concentric with the axis Y ofshaft I4.

large gear I8 which may conveniently serve as a fly wheel and is inconstant mesh with a bed motion driving gear I9. The ratio between gearsIB and I9 is three to one, that is, gear I9 revolves three times foreach single revolution of gear I8. Gear I9 is secured to a shaft 20which is journaied in suitable bearings 2l and 22, respectively, theseelements being standard parts of presses of the type here mentioned.

Because of the lateral shifting of pinion 2 by the bar and thesimultaneous rotation of gears 23 and 24 in opposite directions, thecrank arms move consecutively into and out of cooperative engagementwith the pinion and accordingly, for at least a part of their rotation,the crank arm of one gear will drive or rotate the pinion 2 in onedirection and the crank arm of the other gear will drive or rotate it inthe reverse direction.

As the slide bar moves to the left, as viewed in Figure 3, the crank armof gear 23 is disposed within the channel 28 of pinion 2 and therebycauses it to rotate lrst in one direction and then the other andconsequently effect reciprocation of the bed I. When the sliding harreaches the limit of its travel, the crank arms are disposed insubstantially horizontal positions, as seen in Figure 3, so that thechannel 23 may move from operative engagement with the crank arm or gear23 into cooperative engagement with the crank arm of gear 24.

Crank arm of gear 23 will continue to rotate but Without eiectingrotation of pinion 2. When the crank arm of gear 24 moves intoengagement with the channel 23, the roller I6 of pivoted arm 9 is justentering the concentric part of the groove I5 in the larger end of thecam I3 and during the time the roller moves relatively from one end ofthis concentric path to the other, slide 5 and therefore the axis of thepinion 2 remains stationary. The gears 23 and 2Q continue to revolvehowever, and the crank arm of gear 24 consequently rotates pinion 2 forapproximately one revolution while the slide 5 is stationary.

Upon completion of this revolution of the crank arm, the cam then,acting through lever 9 and roller I5, pulls or moves the shifting bar 5to the right. In Figure 5 of the drawings showing the relative positionof the parts after the gears have rotated 90 from the horizontal andpinion 2 has been shifted by movement of the bar 5, it will beappreciated that the crank arm in moving from the position indicated inFigure 3 to the position shown in Figure 5 is in operative engagementwith the under side of the uppermost flange of the channel and has,therefore, caused the pinion 2 to rotate in the same direction as thegear 24, as indicated by the arrows in Figure 5.

As rotation of the crank arm of gear 24 continues the direction ofrotation of pinion 2 is reversed because the axis of rotation of pinion2 continues to shift toward the right and the crank arm, therefore,presses on the upper side oi the lower flange of the channel. Thus ascrank arm of gear 24 moves from the upright position indicated in Figure5 to the horizontal position of Figure 6, the direction of rotation ofthe pinion 2 is reversed, The crank arm of gear 2icon tinues to rotatethe pinion in the direction indicated by the arrow in Figure 6, whilethe axis of rotation of the pinion is being moved to the right until theshifting bar 5 reaches its extreme right position. The relativepositions of the pinion and the crank pins at the time the crank pin ofgear 24 moves from engagement with channel 28 of pinion 2 and the crankarm of gear 23 moves into operative engagement therewith is shownapproximately in dotted lines in Figure 7. At the time the crank armsrespectively move into and out of engagement with the channel of thepinion, they both exert forces on the pinion to rotate it in the samedirection. Thus no abrupt shock or sudden change in direction ofrotation of the pinion is accomplished when it moves from cooperativeengagement with one crank arm into cooperative engagement with theother.

Pinion 2 is moved into the extreme right position shown in full lines inFigure 7 just as the roller IB on the arm il enters the part of thegroove I5 of the cam at the smaller end thereof which is concentric withthe axis of rotation of the shaft. This concentric portion of tle cam,like the concentric portion at the opposite end thereof, affords a dwellwhereby the sliding bar 5 is held immovable while the gears 23 and 24continue to rotate. The dwell in the smaller portion of the cam is suchthat the pinion 2 may be rotated the desired amount while the axis ofthe pinion is held stationary.

After rotating with its axis held immovable, the bar carrying the shaftof pinion 2 then shifts toward the left and the cranks operate in themanner described whereby the direction of rotation of the pinion isreversed by the crank arm of gear 23 during the rst half revolution ofthe gear.

By causing the bed to reciprocate in this manner, it is not subjected tosudden or abrupt shocks each time its direction of movement is changed.Reversal of rotation of the pinion 2 takes place slowly and evenlyduring each stroke of the sliding bar when the turning movement of thepinion is at a minimum. The speed of rotation of the pinionprogressively decreases to zero in oneiourth revolution of the crankduring initial shifting of the bar 5, then reverses and progressivelyincreases to normal speed in the next quarter revolution of the crank atwhich time the crank of the other gear is moving into engagement withthe channel of the pinion.

Thus simple and reliable means have been provided for successivelyreversing the direction of movement of the press bed which does notimpart sudden or abrupt shocks to the bed or to the reversing mechanism.Various changes may be made in the details of the structural embodimentof the invention here illustrated and described without departing fromthe spirit of the invention as described in the appended claims.

What I claim is:

l. The combination with a reciprocating member having a rack securedthereto, of mechanism for reciprocating said member involving a pinionin mesh with said rack, a slidable support for said pinion, means formoving said support back and forth, and a plurality of rotatable meansconsecutively cooperable with said pinion upon each change in thedirection of movement of said member for respectively reversing thedirection of the pinion.

2. The combination with a reciprocating member having a rack securedthereto, of mechanism for reciprocating said member involving a pinionin mesh with said rack, means slidable back and forth carrying saidpinion, and revoluble members consecutively cooperable With said pinionduring sliding movement of said means for rotating said pinion, each ofsaid revoluble members reversing the rotation of the pinion duringmovement of said means in one direction.

3. The combination with a reciprocating member having a rack securedthereto, of mechanism for reciprocating said member involving a pinionin mesh with said rack, a slidable support for said pinion, means formoving said support back and forth, and a pair of oppositely rotatinggears for rotating said pinion, said gears respectively having meansconsecutively engageable with said pinion upon each change in thedirection of movement of said support for respectively reversing thedirection of rotation of the pinion.

4. The combination with a reciprocating member having a rack securedthereto, of mechanism for reciprocating said member involving a pinionin mesh with said rack, slidable means on which said pinion is mounted,a pair of meshing gears adjacent said pinion respectively provided withcrank arms, and means rigid with said pinion consecutively engageable bysaid arms upon each change in the direction of movement of said memberfor rotating the pinion, each of said crank arms being adapted toreverse the direction of rotation of the pinion while in operativeengagement with said means.

5. The combination with a reciprocating member having a rack securedthereto, of mechanism for reciprocating said member involving a pinionin mesh with said rack, a slidable support for said pinion, means formoving the support back and forth, a pair of oppositely rotating gearsrespectively having eccentric portions spaced laterally of said pinion,means on the face of said pinion adjacent said gears engageable by saideccentric portions for rotating the pinion, said eccentric portionsmoving consecutively into and out of engagement with said means on thepinion for effecting periodic reversal of rotation of said pinion.

6. The combination with a reciprocating member having a rack securedthereto, of mechanism for reciprocating said member involving a pinionin mesh With said rack, a slidable support for said pinion, means formoving the support back and forth, a pair of rotatable devices mountedto one side of said pinion and respectively having eccentricallydisposed members for rotating the pinion, the axis of rotation of saiddevices being substantially parallel with the axis of rotation of saidpinion, said eccentric members being consecutively engageable with saidpinion and each being adapted to first rotate it in one direction andthen in the reverse direction.

7. The combination With a reciprocating member having a rack securedthereto, of mechanism for reciprocating said member involving a pinionin mesh with said rack, a slidable support for said pinion, means formoving the support back and forth, a pair of meshing gears respectivelyhaving crank arms for rotating said pinion, and channel-shaped means onthe side of said pinion adjacent said gears consecutively engageable bysaid crank arms, the rotation of said crank arms being timed withrespect to the sliding movement oi said pinion so that each crank armwill first cause the pinion to rotate in one direction and then in thereverse direction.

8. In a reciprocating bed motion for ilat bed printing presses, thecombination of a rack secured to the reciprocating bed, of a pinion inmesh with said rack, a sliding bar on which said pinion is rotatablymounted, means for moving said bar back and forth, oppositely rotatablegears adjacent said pinion, each of said gears being provided with acrank arm for rotating the pinion, and means rigid with the pinionengageable by the crank arm of one of said gears to rotate the pinionfirst in one direction and then in the reverse direction during slidingmovement of the bar in one direction and engageable by the crank arm ofthe other of said gears to similarly rotate the pinion during slidingmovement of the bar in the opposite direction.

9. In a reciprocating bed motion for flat bed printing presses, thecombination of a rack secured to the reciprocating bed, of a pinion inmesh with said rack, a sliding bar on which said pinion is rotatablyjournaled, means for moving said bar back and forth, a pair of meshinggears disposed adjacent said pinion respectively having crank arms forrotating the pinion, and means carried by said pinion consecutivelyengageable by said arms upon each change in the direction of movement ofsaid bar for rotating the pinion, each of said crank arms being adaptedto cause the pinion to rotate in opposite directions while said bar ismoving in one direction.

l0. In a reciprocating bed motion for flat bed printing presses thecombination of a rack secured to the reciprocating bed, of a pinion inmesh With said rack, a sliding bar in which said pinion is rotatablycarried, a shaft including cam means for moving said bar back and forth,a pair of gears adjacent said pinion respectively provided with crankpins, means rigid with one of said gears and driven in response torotation of said shaft for rotating said gears, and channelshaped meansrigid with one of the side faces of said pinion consecutively engageableby said crank pins whereby each crank pin is adapted to rotate thepinion first in one direction and then in the reverse direction Whilesaid bar is being moved in one direction.

11. The combination with a reciprocating bed having a rack securedthereto, of mechanism for reciprocating said bed involving a pinion inmesh with the rack, means for shifting said pinion laterally to and fro,a pair of oppositely rotating gears adjacent said pinion respectivelyhaving crank arms consecutively cooperable with said pinion for rotatingit, each of said cranks when initially brought into cooperation with thepinion continuing to rotate it in the same direction as last rotated bythe other crank and being adapted to reverse the direction of rotationthereof as the pinion is being shifted laterally.

l2. The combination with a reciprocating bed having a rack securedthereto, cam means for shifting said pinion laterally to and iro, a pairof oppositely rotating gears respectively having crank armsconsecutively cooperable with said pinion for rotating it, said cammeans having concentric portions so that when said pinion is initiallyengaged by either of said cranks it continues to rotate without shiftinglaterally for approximately 360 in the same direction as last rotated bythe other crank, and each of said cranks being adapted to reverse thedirection of rotation of the pinion as it is being shifted laterally.

FREDERICK R. MOLITOR.

